Method of baling

ABSTRACT

A large-capacity baling apparatus having a horizontally disposed compression chamber directly loadable at its upper portion and including transversely moveable means for shifting the compressed medium from the compression chamber into a strapping chamber wherein compression and strapping occur in nonaligned, separate chambers.

United States Patent 1111 Wright 1 1 Oct. 2,- 1973 [54] METHOD OF BALING 3,088,499 5/1963 Riegcr 100/218 X 3,017,730 1/1962 Rodish 100/218 X Inventor; C011" Wrlght Ann Arbor, Mlch- 2,984,172 5/1961 Roberts ct 111. 1011 2111 x I 2,500,819 3/1950 Hall ct a1. 100/218 X [73] Assignee: American Hoist & De ic 2,780,989 2/1957 Guy 100/218 Paul FOREIGN PATENTS OR APPLICATIONS 22 Filed; Jam 1971 965,906 8/1964 Great Britain 100/3 [2H Appl' 107905 Primary Examiner-Bil1y J. Wilhite Related US. Application Data I A!10rneyBeam and Beaman Division of Ser. No. 876,214, Dec. 1, 1969, which is a continuation of Ser. No. 661,070, Aug. 16, 1967, [57] ABSTRACT abandoned.

A large-capacity baling apparatus having a horizontally [52] US. Cl. 100/3 disposed compression Chamber directly loadable at its [51] Int. Cl Bb 13/02 pp portion and l ng r ly m ve bl [58] Field of Search /3, 7, 25. 26, means for Shifting the compressed medium from the 100/188, 218, 232, 9, 99 compression chamber into a strapping chamber wherein compression and strapping occur in non- [56] References Cit d aligned, separate chambers,

UNITED STATES PATENTS 2 Claims. 10 Drawing Figures 583,462 6/1897 Dederick 1 1 1 100/9 646,520 4/1900 Dederick 100/99 679,732 8/1901 Dederick 100/9 V 5 2 2525 55 i m j [l l] I PATENTEUUU 2191s SHEET 1 RF 5 N wNDT INVENTOR COLIN s. WRIGHT ATTORNEYS mqAwxm PATENTED URI 2 I973 SHEET 2 BF 5 INVENTOR COLIN s. WRIGHT ATTORNEYS PATENTED UB1 2 I973 SHEET 3 UF 5 m w nu I III I I I I l I ll 6 w U 5 I 0 4 2 a 6 G .1 I k F A 9w" I \4 Q & m

ATTORNEY5 PATENTED Um 21975 3.762 .310

SL315? HF S INVENTOR COLIN S. WRIGHT ATTORNEYS METHOD or BALING CROSS REFERENCE TO RELATED APPLICATIONS This application is a division of Ser. No. 876,214 filed Dec. 1, 1969, now U.S. Pat. No. 3,576,161 which application is a continuation of application Ser. No. 661,070 filed Aug. 16, 1967, now abandoned.

BACKGROUND OF THE INVENTION The invention relates to the field of baling loose, compressible medium such as paper, cardboard and the like wherein compression is produced in a horizontally disposed compression chamber by means of a hydraulic ram, and the compressed medium is transferred from the compression ram for strapping purposes.

Baling apparatus for scrap materials, such as paper, cardboard and the like which is of the so-called high capacity type capable of producing relatively large, high-density bales, and baling a large tonnage in a given time period are usually of two types, vertical or horizontal. Vertical baling equipment employes a compression chamber which is vertically disposed, and the horizontal type balers use a compression chamber horizontally disposed.

Large vertical chamber balers receive the material to be baled within the compression chamber and a ram, either hydraulic or mechanical, is moved vertically, usually upperwardly, to compress the material at an end region of the chamber. After several compression strokes, with additional material being introduced into the chamber between strokes, a bale is formed in the end portion of the chamber and strapping of the bale occurs while it is located within the compression chamber. This arrangement has the disadvantage of rendering the baler inactive while strapping of the bale occurs. Additionally, vertical chamber baling devices have relatively small compression chamber loading openings due to the constructional limitations of this type of baler.

Horizontally disposed balers, such as represented in U.S. Pat. No. 3,212,434, consist of an elongated, open end, horizontal chamber into which the material to be compressedis introduced. Ram or compression means periodically reciprocate within the chamber to force the medium being compressed into and through the compression chamber. The compression chamber is so shaped that the resistance of movement of the medium through the chamber produces a sufficient compression and density. When the medium has achieved the desired density, a predetermined portion of the compressed material is strapped as it periodically moves through a finalstage of the compression chamber. In order to facilitate strapping, dividers are periodically inserted into the medium being compressed wherein the bale straps may be inserted through the compressed material and produce the strapping of the bale. In a horizontal baler of conventional construction the density of the material being compressed fluctuates with the movement of the ram or plunger and control of the density, and size of the bale is difficult to regulate.

Conventional baling apparatus of the vertical and horizontal type usually requires that paper and cardboard be shredded or hogged prior to being introduced into the compression chamber. Such shredding is primarily necessitated by the inability of the loading openings of conventional baling apparatus to accommodate large boxes and paper sheets, and it is usually necessary to employ shredding means with the balers in order to permit the most efficient and effective use of the balers.

Conventional vertical and horizontal compression chamber balers do not lend themselves to automatic strapping mechanisms, as such automatic devices can only be used with great difficulty in the limited clearance and space available with a vertical baling apparatus, and automatic strapping devices are very difficult to use with horizontal balers in that the portion of the compressed medium which constitutes a bale is moving through the compression chamber while it is being strapped.

Large'capacity baling apparatus of conventional arrangement and structure requires at least three or four men in order to obtain maximum output of the baler, and the nature of the equipment is such as to require considerable manual operation and supervision.

SUMMARY OF THE INVENTION The invention pertains to a method of baling of unique design which is capable of baling large tonnage in a relatively short time interval with a minimum of labor and supervision.

After the desired material has been compressed to a high density, the degree of compression is reduced and a traverse ram or plunger is actuated which moves at right angles to the compression ram and transfers the compressed material from the compression chamber directly into a strapping chamber.

. In carrying out the method of the invention in the formation of a bale of compressed paper, cardboard or the like, the bale is formed in a plurality of strokes, resulting in a layered or laminated bale construction. In conventional horizontal baling devices of the type described above such layers or laminations results inthe compressed matter expanding and contracting during strapping due to the pulsation of the compression ram. In the baler disclosed herein the compressed bale is transferred from the compression chamber in a direction parallel to the bale layers and confined in the strapping chamber in a static condition. Thus, the method of operation of the baler in accordance with the invention is capable of producing high density bales and substantially maintaining the density during strapping. By overcompression of the bale in the baling chamber and then reducing the compression a predetermined amount prior to strapping each bale is of a substantially uniform size and configuration which materially simplifies bale handling and storage.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages arising from the functional relationships of the components of an embodiment of the baler illustrating the method of the invention will be apparent from the following description and accompanying drawings wherein:

FIG. 1 is a plan, sectional view of baler apparatusin accord with the invention taken along section 1-1 of FIG. 2,

FIG. 2 is an elevational, sectional view of the baler apparatus of FIG. 1, taken alongSection IIII thereof,

FIG. 3 is an enlarged, detail, sectional plan view of the left half of the baler apparatus, illustrating the cover ram and related components as taken along section lll-lll of FIG. 2,

FIG. 4 is an elevational, detail, sectional view taken through the compression chamber along section IVIV of FIG. 1,

FIG. 5 is an elevational. sectional view illustrating the traverse ram, compression chamber and strapping chamber relationship taken along section VV of FIG.

FIG. 6 is an enlarged, detailed, plan view of the strapping chamber,

FIG. 7 is an elevational, sectional view of the strapping chamber taken along section VIIVII of FIG. 6,

FIG. 8 is a detail, plan, sectional view of the compression chamber and traverse ram taken along a section line similar to that of FIG. 1, illustrating the traverse rarn in the extended relationship for transferring a bale into the strapping chamber,

FIG. 9 is a circuit diagram of the hydraulic control system used with the baler of the invention, and

FIG. 10 is an electrical circuit diagram of the electric circuit used with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE BALER ILLUSTRATING THE METHOD OF THE INVENTION The baler apparatus in accord with the invention consists of a frame 10 which is of a generally L-shape, as will be appreciated from FIG. 1. The base of the frame 10, in the disclosed embodiment, is formed of large channel members, as will be apparent from FIGS. 2 and 4. Parallel channel members 12 form supporting structure for the compression chamber, and parallel channel members 14 disposed at right angles to the members 12 form the base for the traverse ram co'mpartment. The compression chamber is defined by parallel side walls 16, consisting of relatively heavy sheet steel, mounted in a vertical relationship upon the bottom plate 18 which is interposed between and upon the channel members 12. The side walls 16 may extend the length of the U-shaped members 12. Suitable reinforcing members are associated with the side walls 16 to maintain the side walls in the proper relationship, and in the compression region the side walls are reinforced by vertically disposed bracing elements 20, FIG. 4. An elongated cover track and reinforcing member 22 is affixed to the upper edge of each of the side walls 16, FIG. 4, and extends a slight distance inwardly with respect to the side walls.

With reference to FIG. 1, the portion of the side walls 16 to the right of section IVIV partially form the compression chamber 24, and the portion of the side walls to the left of section IVIV constitute an enclosure for the compression ram or plunger 26 of the baler. Preferably, the compression ram 26 takes the form of a large hydraulic cylinder having a piston 28 reciprocal therein. The ram 26 is mounted at one end upon support structure 30 affixed to the members 12, FIG. 2, and is attached at its rear end to the end wall 32 of the frame. The ram 26 is centrally disposed between the side walls 16 and parallel thereto. The piston 28 is provided with a plunger head or wall element 34 of an elevational rectangular configuration, FIG. 4, mounted upon a carriage 36 having antifriction rollers or wheels 38 mounted thereon. The upper rollers 38 engage the underside of the elongated members 22, while the lower rollers engage the bottom plate 18, and thereby support the piston mounted wall 34.

The side walls 16 terminate at ends 40, FIG. I, and the compression chamber portion 42 substantially extending from the side wall ends to the ram wall or head 34 is open at its upper portion defining an elongated loading opening 44 of the width substantially equal to the width of the compression chamber, and of a length substantialy equal to the length of movement of the piston and head during compression of the medium to be baled.

The compression chamber loading opening 44 is closed during compression by an elongated cover 46 adapted to be selectively disposed within the loading opening. The cover 46 is of a length slightly greater than the length of the opening, and includes a downwardly extending portion 48, FIG. 4, which substantially aligns with the underside of the member 22. Wheels or rollers 50 are rotatably mounted upon the cover and engage the upper surface of the members 22 and movement of the cover to open and close the loading opening 44 is accomplished by actuation of the cover ram 52 which consists of a hydraulic motor having a piston 54 affixed to the cover. The cover ram 52 is attached to the frame and extension of the piston will shift the cover from the retracted position shown in full lines in FIG. 2, to the dotted lines position of FIG. 2, which closes the loading opening 44. Parallel angle members 56 affixed to the elongated members 22 include a horizontally disposed portion which overrides the longitudinal edges of the cover, and prevents the cover from lifting from the members 22.

The cover 46 and ram 52 are positioned below an upper plate 58 mounted upon the frame 10, and the control console 60 is mounted upon the plate 58. As is apparent in FIGS. 1 through 3, a housing 62 for the motors 64 and associated pumps is attached to the frame offset with respect to the channel members 12. Control components 66 are also mounted within the housing.

The portion 68 of the compression chamber remote from the compression ram is defined by a movable end wall 70 which may be moved toward the head 34 in its normal position during compression and moved to the right, FIG. 1, by rams 72, during bale transfer. The compression chamber portion 68 is covered by a top wall 74 which is of high-strength characteristics and reinforced by reinforcing members 76. The top wall 74 extends toward the compression chamber portion 42 only slightly beyond the side wall ends 40 and, of course, it will be appreciated that the length of the access loading opening 44 of the compression chamber will be axially defined by the edge of the top wall 74 positioned at dotted line 78, FIG. 1, and the position of the cover 46 when in the retracted position, as in FIG. 2.

A traverse ram chamber is defined upon the frame 10 by side walls 82, and an end wall 84 mounted upon the channel members 14, FIG. 4. The chamber 80 con tains the traverse ram 86 which consists of a hydraulic motor having a piston 88. A wall or plunger is mounted upon the outer end of the piston 88 and is of a rectangular configuration to enclose that portion of the compression chamber 68 intermediate the adjacent side wall end 40 and the end wall 70, and the bottom plate 18 and the top wall 74, when the traverse ram is in the retracted position shown in FIG. 1. The wall or plunger 90 is provided with a box-like rectangular shroud 92, FIGS. 5 and 8, which is of a length slightly greater than the width of the compression chamber 24 and is supported upon rollers 94 engaging the bottom plate 18. The ram 86 is affixed to the frame at 96 and 98, and is of sufficient length to move the wall 90 from the retracted position shown in FIGS. 1 and 5, to the extended position illustrated in FIG. 8.

The compression chamber is provided with a discharge opening 100 defined by the end 40 of the side wall disposed adjacent the strapping chamber 102, the bottom plate 18, the end wall 70 and the top wall 74. The discharge opening 100 is in directly opposed relationship to the moveable wall or plunger 90 and the compressed medium is transferred through the discharge opening into the strapping chamber by the traverse ram 86.

The discharge opening 100 is selectively opened and closed by a gate 104 slidably mounted on the frame in Y the longitudinal direction of the compression chamber.

The gate 104 is operated by a hydraulic ram 106 having a piston 108, and suitable guides and supports are associated with the gate to adequately support the gate at all times. In FIG. 1 the gate is illustrated in the operative or compressing position to close the discharge opening. Retraction of the ram piston 108 withdraws the gate completely from opening 100 to provide full access through the opening, as shown in FIG. 8.

The strapping chamber 102 is mounted upon support elements 110 and is of a generally rectangular configuration having an open inlet end 112 and an open outlet end 114. The disclosed strapping chamber includes a plurality of rollers which are closely disposed to each other for permitting the compressed material to be translated into the strapping chamber with a minimum of friction. The strapping chamber includes a plurality of lower rollers 116 disposed in a horizontal relationship wherein the uppermost portion of the rollers is in substantial horizontal alignment with the compression chamber bottom plate 18. The sides of the compression chamber are defined by a plurality of parallel rollers 118, the innermost portion of the side rollers at the right of FIG. 7 being in substantial alignment with the end wall 70, and the innermost portion of the side rollers at the left of FIG. 7 being in substantial alignment with the end 40 of the adjacent compression chamber side wall. The strapping chamber 102 includes suitable frame work and support components for the rollers, and the support components are so related as to define a plurality of slots 120, FIG. 6, intermediate predetermined side and bottom rollers. Strap guides 122 are associated with the slots defined in the upper portion of the strapping chamber, and a strap guide 124 is associated with the rear of the strapping chamber. Likewise, the strapping chamber is provided with lower strap guides 126 disposed between the bottom rollers 116.

The outlet 114 of the strapping chamber extends away from the baler apparatus, and a bale receiving dock, platform or conveyer will be disposed adjacent the strapping chamber outlet to receive the strapped bale upon the bale being ejected from the strapping chamber.

Operation of the baler in accord with the invention is semiautomatic and the control means are illustrated in FIGS. 9 and 10.

In the disclosed embodiment two electric motors 64 are employed which are preferably each of 75 l-1.P., and each are operatively connected with a hydraulic pump 128 and a hydraulic pump 130. The pumps 128 are of a high capacity, low pressure type capable of pumping gallons per minute at pressures approaching 1,500 pounds per square inch. The pumps 130 are of low capacity, high pressure capable of pumping 50 gallons per minute at pressures exceeding 2,500 pounds per square inch. The output of the pumps 128 and 130 is normally supplied to'the primary pressurized conduit 132. However, when the pressure within the conduit 132 exceeds 1,500 pounds per square inch the control conduit 134 actuates bypass valve 136 to bypass the output of the low pressure pumps 128 into the hydraulic fluid reservoir.

Control of the compression ram 26 is accomplished by a hydraulically operated valve 138 of the Olmstead type. The portion 140 of the control valve 138 is associated with the end of the ram producing piston extension, and the valve portion 142 is associated with the piston rod end of the ram. Small hydraulic cylinders 144 control the operation of the valve 138, and the control cylinders 144 are operated by the primary pressure on valves 143 and 145 controlled by the solenoids 146 and 148, respectively.

Pressure switches 154 and 156 communicate with the extension end of the ram 26 to sense the pressure within the ram during compression of the medium being baled. Switch 154, as will be later described, is used to sense the pressure during compression and regulate the regeneration operation. Pressure switch 156 is employed to sense the occurrence of the desired compression pressure.

Operation of the traverse ram 86 is controlled by the hydraulically actuated valve 158, which is shifted between its various positions by control cylinders 160. Control cylinders 160 are operated by the valve 162 controlled by solenoids 164 and 166.

As the cover ram 52 does not require the volume and pressures of the compression and traverse rams, control of the cover ram is directly accomplished through valve 168 which is shifted between its operative positions by solenoids 170 and 172. Likewise, the gate ram 106 may be directly controlled by valve 174 and solenoids 176 and 178, and the wall rams 72 are connected in'parallel with ram 106.

The pressure within the hydraulic circuit is regulated by pressure control apparatus including the hydraulically operated valve 180 controlled by control cylinders 182 and 184. The cylinder 182 is energized through the valve 186 actuated by solenoid 188, and the control cylinder 184 is operated by the primary pressure source of the system. A pressure relief valve which opens at 2,500 pounds per square inch communicates with the pressure conduit 132 and the primary pressure also communicates with a valve 192 operated by solenoid 194. The valve 192 communicates with a pressure relief valve 196 which opens at 2,000 pounds per square inch to return the fluid to the reservoir. The flow of fluid through the pressure relief valve 196 occurs as long as the valve 192 is in the open position illustrated, and the position illustrated is the normal operating position of the system. Solenoid 188 must be energized at all times when pressure is required in the system, otherwise, the valve 186 will shift to a position causing the valve 180 to exhaust directly to the reservoir. Energizing of the solenoid 188 causes the fluid to flow through the valve 192 and the pressure relief valve 196 to maintain 2,000 pounds per square inch pressure in the system. Should pressures higher than 2,000 pounds per square inch be momentarily desired to properly orient the rams, for instance, if the operator permited more material to be placed in the compression chamber 24 than intended, higher pressure is produced by energizing solenoid 194 to prevent flow through valve 192 and render pressure relief valve 190 operative to control the pressurized system.

The electrical circuit used in the control of the baler apparatus is illustrated in FIG. 10 and switches operated by a common relay are designated by primes.

Power for the circuit is provided through a transformer 198 and switch 200 represents a manual standby switch while lamp 202 indicates energization of the power. The pump motors 64 are controlled by stop switches 204, and start switches 206, and include the usual overload switches 208 and pilot lights to indicate energization of the pump motors. The control of solenoid 148 includes a stopswitch 210, a double contact cycle switch 212, a double control limit switch 214, jog switch 216 and pressure switch 154. Normally open relay switch 220' is controlled by time delay relay 220, as is normally closed relay switch 220". The circuit also includes an isolating switch 236 and the limit switch 238 is connected in series with a second portion of limit switch 214. Normally open relay switch 220" bridges limit switch 238 and the circuit includes the normally open relay contact switch 218'.

The compression ram control circuit further includes limit switch contacts 256' and a jog forward switch 242. The second contacts of switch 212 are in series with pressure switch 156 and relay 222 includes normally open contacts 222', while normally closed contact 220"" of relay 220 are included in series with the pressure switch 156. The solenoid 146 is operated by the circuitry described immediately above.

The traverse ram control circuit includes the stop switch 244. Limit switches 246 and 247 are connected in series with the cycle switch 248 and the limit switch 250. Cycle switch 248 is bridged by normally open contacts 224 of relay 224 and limit switch 250 is in series with the normally closed contacts 226 of time delay relay 226. Relay 224 is connected in parallel with solenoid 166 and a jog forward switch 252 is included in this circuit. A jog retract switch 254 is connected in series with the solenoid 164 and the circuit to relay 226 includes limit switch 256, limit switch 258 and normally open relay switch 226", and normally closed relay switch 224". The solenoid 164 and relay 226 are bridged by the normally open relay switch 226".

Control of the cover ram 52 is accomplished through a circuit including stop switch 260 and start switches 262 and 264. Switch 262 is bridged by normally open relay contacts 228' and switch 264 is bridged by normally open relay contacts 230'. Solenoid 170, and relay 228 are connected in series with limit switch 266 and the normally closed relay contacts 230". Solenoid 172 and relay 230 are in series with the limit switch 268 and the normally closed relay contacts 228".

The gate ram 106 includes in its circuit the stop switch 270 and start switches 272 and 274, bridged by normally open relay contacts 232 and 234', respectively. Solenoid 176 and relay 232 are in series with limit switch 276, and normally closed relay contacts 234". Solenoid 178, and relay 234 are in series with limit switch 278 and normally closed relay contacts 232".

As solenoid 188 is to be energized whenever pressure is required in the system, which is most of the time, the

normally open relay contacts 218", 222", 224", 226", 228", 230", 232", 234" are connected in parallel with the circuit to the solenoid 188, as well as are the jog switches 280.

In the event that a 2,500 pounds per square inch fluid pressure is desired, the solenoid 194 is energized by the manually operated switch 282. The switch 282 is of the type which must be manually depressed as the requirement for the higher pressures resulting from energization of the solenoid 194 will only be momentary.

The limit switches described above are mounted upon the baler structure for actuation by the appropriate pistons, plungers, gates, etc., and the approximate location of the switches is diagrammatically indicated in FIGS. 1 and 2.

The operation of a baler apparatus in accord with the invention is as follows:

Loading of the baler apparatus occurs when the compression chamber loading opening 44 is fully open and the compression, cover and traverse rams are in the retracted positions shown in FIGS. 1 and 2. In the preferred embodiment of the invention the distance separating the compression chamber side walls 16 is substantially 60 inches, while the longitudinal length of the compression chamber loading opening 44 is substantially inches. The unusually large size of the access opening permits bulky boxes, cartons and other scrap paper articles to be introduced into the compression chamber without the need for shredding or hogging the scrap articles. The vertical dimension of the compression chamber is substantially 36 inches, and the aforementioned dimensions permit the compression chamber to be quickly loaded by means of a conveyer or other mechanical material handling apparatus. As the baler is of the horizontal type, it is possible to locate the baler below floor level wherein material to be baled may be directly pushed into the compression chamber by a bulldozer or the like. Of course, the baler apparatus may be mounted upon a ground level supporting surface, rather than being located within a pit, and in such instance a loading platform would probably be lo-' cated adjacent the compression chamber opening on a horizontal level therewith to aid in introduction of the material into the compression chamber.

When the compression chamber has been filled, the operator located at the console 60 will energize the primary motor switches 206, if the pump motors 64 have not already been started. The swtich 262 is closed to energize solenoid to shift valve 168 to extend the cover. rim and close opening 44. The operator then closes cycle switch 212 which energizes solenoids 146 and 148 which produces an actuation of the valve 138 permitting pressurized fluid to be introduced into the left, or extension end of the compression ram 26, FIG. 9, to begin extending the piston 28 and moving the compression ram wall or plunger 34 toward the end wall 70. During the initial stage of compression the valve portion 142, as energized by valve 145, is positioned such that the fluid being exhausted from the piston rod side of the compression ram is introduced into the pressurized circuit, and the supply conduit 132 and extension side of the ram 26. This utilization of the hydraulic fluid exhausted from the compression ram constitutes a regeneration cycle permitting a maximum amount of pressurized fluid to be introduced into the compression ram and produce an initial rapid movement of the compression ram.

During the initial movement of the compression ram the pressurized fluid conduit 132 will be receiving fluid from both pumps 128 and both pumps 130, in that the pressure within the system will be less than 1,500 pounds per square inch. When the resistance to movement of the compression ram becomes great enough to cause the fluid pressure within the supply conduit to reach approximately 800 pounds per square inch, such a condition is sensed by the pressure switch 154. Pressure switch 154 then opens and deenergizes solenoid 148 which shifts valve portion 142 from the regeneration position, to the exhaust-to-reservoir position shown in FIG. 9. The compression ram piston will continue to compress the material within the compression chamber, and upon the pressure within the supply conduit 132 reaching 1,500 pounds per square inch, the bypass valve 136 will open to bypass the output of the low pressure-high volume pumps 128 into the fluid reservoir. Continued pressurizing of the compression ram is now accomplished solely by the two low capacityhigh pressure pumps 130. The purpose for removing pumps 128 from the operative system at 1,500 lbs. per/sq. in. is to permit the desired fluid pressures to be developed with electric motors of approximately 75 I-I.P. each.

Completion of the first stroke of the compression ram is sensed by the limit switch 238 located adjacent the entrance to compression chamber portion 68. Closing the limit switch 238 will energize relay 220 and thereby energize solenoid 148 and deenergize solenoid 146. This operation permits pressurized fluid to be introduced into the piston rod end of the compression ram and retract the ram. The compressed material will stay within the compression chamber portion 68 when the compression ram is retracted.

Retraction of the compression ram 26 is sensed by the limit switch 214 which opens to hold the retracted ram on manual standby" by deenergizing solenoid 148. After the cover 46 is retracted additional material to be compressed'is introduced into the compression chamber through opening 44 and the above cycle is repeated. Several loadings, usually three or'four, of the compression chamber will be necessary before the desired density bale has been achieved. Of course, the number of cycles of the compression ram will be determined by the amount of material introduced into the compression chamberwith each loading, and the nature of the material being compressed.

On the final compression ram stroke the operator must isolate the retracting limit switch 238, and thus the isolating switch 236 will be opened. This operation will prevent the automatic return of the compression ram. As the final compression stroke will produce a pressure within the compression ram which has been preset in pressure switch 156, the desired fluid pressure will actuate pressure switch 156 and deenergize solenoids 146 and 148 to place the valve 138 in a neutral position. The compression ram extends to its limit wherein the moveable compression wall or plunger 34 is substantially aligned with the ends 40 of the side walls 16 as in FIG. 8. During the final compression stroke, should the operator have misjudged the amount of material within the compression chamber 24, and find that the usual working pressure of 2,000 lbs/sq. in. is insufficient to position the compression ram in the "traverse position of FIG. 8, the operator may momentarily close switch 282 to activate solenoid 194 and valve 192 to raise the working pressure to 2,500 lbs/sq. in. and thus, position the compression ram wall as illustrated in FIG. 8. If this operation is insufficient to permit extension of ram 26 to its limit, retraction of the rams 72 when the gate cam 106 is retracted will permit wall to move and thereby reduce the compression enough so ram 26 can fully extend.

The limit switch 250 is preferably of the magnetic detector type, and a magnet located upon the compression ram structure energizes the limit switch 250 when the compression ram wall 34 is in the position shown in FIG. 8. Closing of the limit switch 250 will prepare the traverse ram circuit for energization.

It will be appreciated that it is necessary to close the compression chamber loading opening 44 during each compression stroke of the compression ram. Thus, prior to initiating each compression stroke of the compression ram, the operator will close switch 262, which energizes solenoid 170 and introduces pressurized fluid into the extension portion of the cover ram to roll the cover over the compression chamber loading opening.

When the cover is in place, as represented in dotted lines in FIG. 2, the compression ram cycle may be actuated. Retraction of the cover is produced by closing switch 264 to energize solenoid 172. Rather than the semiautomatic control of the cover ram as described above, it is within the scope of the invention to interlock the control switches 262 and 264 with the compression ram cycle circuit wherein the cover 46 will automatically slide into a closed position as the compression ram is moved forward and retract from the access opening when the compression cam is retracted. Limit switch 266 senses the closed position of the cover and opens when the cover is fully closing opening 44, and limit switch 268 senses full retraction of the cover ram and deenergizes the circuit at complete retraction.

When the compression ram is in the position locating the wall 34 adjacent the ends 40 of the sidewalls, as in FIG. 8., the operator closes switch 274 to energize the solenoid 178 and gate ram valve 174 and retract the piston 108 to pull the gate 104 from the compression chamber discharge opening 100. The opened and closed positions of the gate 104 are sensed by the limit switches 278, 276, and 246. Limit switch 247 closes upon wall 70 and rams 72 fully retracting. Thus, limit switches 246 and 247 deenergize the traverse ram circuit as long as the gate closes the compression chamber discharge opening 100 and the rams 72 are extended.

The operator now closes push-button switch 248 to energize solenoid 166 and relay 224. This operation actuates valve 162, which in turn actuates the hydraulically operated valve 158 to permit pressurized fluid to be introduced into the traverse ram 86 to extend the traverse ram piston 88. As the traverse ram 88 piston extends, the moveable wall 90 is pushed across the compression chamber portion 68 and pushes the compressed material therein through the discharge opening into the strapping chamber 102. The movement of the traverse ram wall 90 will continue until the moveable wall is positioned as shown in FIG. 8., substantially within the strapping chamber inlet end 112. At this time the compressed material will be fully received within the strapping chamber.

Limit switch 256 is located at the entrance 112 of the strapping chamber and will sense the full extension of the traverse ram 86. The limit switch 256 will automatically return both the compression ram, through contacts 256', and the traverse ram to retracted positions as the limit switch energizes the solenoids 148 and 164 two or three seconds after the traverse ram has penetrated the strapping chamber inlet. Limit switch 258 will sense the retracted position of the traverse ram and hold the traverse ram on manual standby, and limit switch 214 will sense the retracted condition of the compression ram, and likewise, maintain the compression ram in a manual standby condition.

The operator closes switch 272 to actuate solenoid 176 and relay 232 to extend the gate ram 106 and locate the gate within the compression chamber discharge opening 100 and extend rams 72 to move wall 70 toward head 34. Also, the operator will close switch 264 and energize solenoid 172 to retract the cover ram 52 and provide access to the compression chamber portion 42 for loading with new material to be compressed.

Compression of the material has usually taken place through several cycles of the compression rarn. Thus, the material within the compression chamber portion 68, prior to being transferred-to the strapping chamber 102, will exist in layers perpendicularly disposed to the axis of the compression ram. Upon the compression material being transferred to the strapping chamber, the tendency for the compressed material will be to expand against the side rollers 118. However, as the side rollers 1 18 will not permit expansion, the dimensions of the compressed material will be closely maintained.

Strapping of the compressed material within the strapping chamber 102 is quickly accomplished by inserting the baling straps 184 into the slots 120 disposed between the rollers 116 and 118. The presence of the band strap guides 122, 124, and 126, facilitates the placing of the banding straps about the bale, and either an automatic or a manual strapping apparatus may be employed to tension and clamp the straps 284.

It will be appreciated that the bale is strapped in the direction as to confine the bale against expansion due to the layering of the compressed material. Thus, upon the bale being removed from the strapping chamber 102, no significant expansion of the bale will be permitted by the baling straps.

Strapping of the bales within the strapping chamber takes place simultaneously while the next bale is being compressed within the compression chamber. Thus, the baler in accord with the invention permits simultaneous bale compression and strapping. The bale previously inserted into the strapping chamber will usually be completely strapped by the time that the subsequently compressed material is ready to be transferred into the strapping chamber. Upon the compressed material within chamber portion 68 being of the desired density, the gate 104 is opened and the traverse ram 86 actuated to introduce the compressed material into the strapping chamber. This operation will push the strapped bale from the strapping chamber 102 through the strapping chamber outlet 114 and onto a conveyor or platform. The traverse ram 86 is retracted, the gate 104 is reinserted into the discharge opening 100 and the strapping and compression cycle repeated.

The fluid pressures and the size of the rams used in the invention permit a very high density bale to be formed. In an embodiment of the invention using the dimensions previously stated, and wherein the dimension of the compression chamber portion 68 parallel to the ram 26 is substantially 48 inches, a bale size 60 X 36 X 48 inches is produced which will weigh between 1,500 pounds and 1,700 pounds. Usually, three strokes of the compression ram will be used when baling mixed corrugated boxes, paper, etc., and the designed cycle time for the compression ram is approximately 25 seconds. The cycle time for the traverse ram is approximately 15 seconds, and the total time to form a complete bale is in the neighborhood of seconds under optimum conditions. Baling apparatus of the disclosed type can be operated efficiently with three attendants, one attendant operating the control console, another attendant supervising the loading of the material, and

the third attendant supervising or producing the strapping of the bale. By using two motors and double pump systems, the baling apparatus is capable of operating at one-half speed should one of the motors or pumps require maintenance.

The movable wall 70 provides a dual function in the operation of the apparatus. Its basic function is to reduce the power requirement of traverse ram 86 when transferring the bale from the compression chamber to the strapping chamber. By retracting wall 70 prior to extending ram 86 the friction between the bale and wall 70 will be reduced as the bale is transferred. Secondly, as previously mentioned, if the compression ram 26'is unable to fully extend during the last compression stroke the retraction of wall 70 will permit this operation and thereby assure that head 34 is properly oriented to opening during transfer of the bale.

It will be appreciated that modifications to the inventive concept may be apparent to those skilled in the art without departing from the spirit and scope thereof and it is intended that the invention be defined only by the scope of the following claims:

I claim:

1. The method of baling paper products wherein the paper products are compressed into a bale to form a plurality of layers comprising the steps of compressing paper products in a first direction to form a parcel of compressed paper products in a compression zone having layers substantially perpendicularly disposed to said first direction with said parcel as initially disposed in said zone being in a state of maximum compression, reducing the compression of said parcel while in said zone a predetermined amount, then transferring said parcel in its state of reduced compression from said zone to a strapping station in a direction substantially parallel to said layers and strapping said parcel into a bale as it is transferred from said zone.

2. The method as defined in claim 1 wherein said reduction in compression is accomplished by permitting said parcel to expand in said first direction a predetermined amount.

* k l i 

1. The method of baling paper products wherein the paper products are compressed into a bale to form a plurality of layers comprising the steps of compressing paper products in a first direction to form a parcel of compressed paper products in a compression zone having layers substantially perpendicularly disposed to said first direction with said parcel as initially disposed in said zone being in a state of maximum compression, reducing the compression of said parcel while in said zone a predetermined amount, then transferring said parcel in its state of reduced compression from said zone to a strapping station in a direction substantially parallel to said layers and strapping said parcel into a bale as it is transferred from said zone.
 2. The method as defined in claim 1 wherein said reduction in compression is accomplished by permitting said parcel to expand in said first direction a predetermined amount. 